Jailed Libor trader to return to London court in battle over assets

(Adds Hayes lawyer comment, details)

By Kirstin Ridley

LONDON, March 11 (Reuters) - Tom Hayes, a former trader serving an 11-year jail sentence for conspiracy to rig Libor interest rates, will next week return to a London court in a multi-million pound battle against prosecutors over assets that include a seven-bedroom country house.

Hayes and his corporate lawyer wife Sarah are both expected to give evidence to try to prevent the seizure of their entire estate, which prosecutors value at 3.8 million pounds ($5.4 million), including Sarah's jewellery, and which they allege has been paid for with proceeds of crime.

Five days of hearings begin on Monday and are expected to focus on the couple's former home in Surrey, southern England, which they bought in 2011 and began to renovate before the Serious Fraud Office (SFO) launched criminal proceedings.

The house, which is now in Sarah's name, has been rented out since the couple moved with their now four-year-old son to a more modest property in Fleet, Hampshire, to be nearer to family.

Hayes's lawyer declined to comment ahead of the proceedings, which the SFO said would take place at the Old Bailey, London's central criminal court.

Cast (Paris: FR0000072894 - news) as the ringleader in a rate-rigging scam that has cost banks billions in regulatory fines, Hayes was found guilty last August of conspiring to rig Libor - an interest-rate benchmark used to set rates on hundreds of trillions of dollars worth of financial contracts and household loans worldwide.

The former Tokyo-based UBS (LSE: 0QNR.L - news) and Citigroup (Swiss: C.SW - news) trader denied dishonesty during his trial and argued in court that he had always been open about trading methods that he said had been condoned by senior managers and was common industry practice at the time. He was handed a 14-year jail sentence. It was reduced to 11 years on appeal.

Hayes, who was diagnosed with mild Asperger's syndrome shortly before his London trial last year, is a gifted mathematician who traded yen-denominated interest rate derivatives tied to Libor - essentially betting against others on the direction of rates.

During the three years he worked for UBS, he made around $300 million for the bank before he was lured away to Citigroup in 2009 with a 2.2 million pound bonus, the court heard during his trial. But Citigroup sacked him in 2010 for attempted rate-rigging as a global investigation, started by U.S (Other OTC: UBGXF - news) . regulators in 2008, swung its focus onto how yen Libor rates were set.

Hayes returned to England, married Sarah and the couple settled briefly in Surrey. In December 2012, Hayes was charged by U.S. prosecutors with fraud-related offences linked to Libor. UK charges followed six months later.

($1 = 0.7032 pounds) (Editing by Jane Merriman)